Advance Construction Technology

1. Advance Construction Technology

2. Topics
• Introduction, uses, selection of pile, types of piles,
pile spacing, group of piles, efficiency of group of
piles, pile cap and pile shoe, load tests on piles, pile
driving, pulling of piles, loads on piles, causes of
failure of piles, pile driving formulas

3. Deep foundation
• Deep foundation are those in which the depth of
the foundation is very large in comparison to its
width.
• Deep foundation are of following types:
• Pile Foundation
• Pier Foundation
• Out of these, pile foundation is more commonly used
in building construction.

4. Deep foundation

5. Pile Foundation

6. Pier Foundation

7. Situations in which Pile foundations is
preferred
• The load of the super structure is heavy and its
distribution is uneven
• The top soil has poor bearing capacity
• The subsoil water level is high so that pumping of
water from the open trenches for the shallow
foundations is difficult and uneconomical
• There is large fluctuations in subsoil water level
• The structure is situated on the sea shore or river bed,
where there is danger of scouring action of water.
• Canal or deep drainage line exist near the foundations
• The top soil is of expansive nature.

8. Situations in which Pile foundations is
preferred

9. Factors affecting selection of type of
Piles
• Location and type of structure
• Ground Conditions
• Durability
• Cost Considerations

10. Types of Piles
• Piles may be classified as follows:
• Classification based on function:
• End bearing pile
• Friction pile
• Compaction pile
• Tension pile
• Anchor pile
• Fender pile
• Batter pile
• Sheet pile

11. Types of Piles
• End Bearing Pile: Are used to transfer the
load through water or soft-soil to a suitable
bearing stratum.
• Friction Pile: Are used to transfer loads to a
depth of a friction load carrying material by
means of skin friction along the length of pile.
• Compaction Pile: Compaction Pile are used to
compact, loose granular soils, thus increasing
their bearing capacity

12. End Bearing Pile

13. Friction Pile

14. Compaction Pile

15. Types of Piles
• Tension or uplift pile: Anchor down the structures
subjected to uplift due to hydrostatic pressure or due to
over-turning moment
• Anchor pile: Provide anchorage against horizontal pull
from sheet pile or other pulling forces
• Fender Pile and dolphins: Are used to protect water
from structures against impact from ships or other
floating objects.
• Sheet Pile: Are commonly used as bulk heads, or as
impervious cut off to reduce seepage and uplift under
hydraulic structures. The batter pile are used to resist
large horizontal or inclined forces

16. Types of Piles

17. Fender Pile

18. Sheet Pile

19. Anchor Pile

20. Miscellaneous Piles

21. Types of Piles
• Classification based on materials and composition
• Pre-Cast
• Cast in situ
• (i) Driven Pile Cased or Uncased
• (ii) Bored Piles: pressure piles,, under-reamed piles and bored compacting
piles.
• Timber pile
• Steel pile
• H-pile
• Pipe pile
• Sheet pile
• Composite Pile
• Concrete and timber
• Concrete and steel
• Under Reamed pile

22. Pre-Cast Pile

23. Cast in situ

24. Timber Pile

25. Steel pile

26. Types of Piles
• Under Reamed Pile: is a special type of
bored pile having an increased diameter or
bulb at some point in its length, to anchor the
foundation in expansive soils subjected to
alternate expansion and contraction

27. Under Reamed Piles

28. Under Reamed Piles

29. Group of Piles
• When several closely spaced piles are
grouped together, it is reasonable to expect
that the soil pressure developed in the soil as
resistance will overlap.
• The bearing capacity of a pile group may or
may no be equal to the sum of the bearing
capacity of individual piles constituting a
group.

30. Group of Piles

31. Group of Piles
• Theory and tests have shown that the total bearing
value Qg of the friction piles, particularly in clay, may
be less than the product of the friction bearing value
Qf of an individual pile multiplied by the number of
piles (n) in a group.
• However, no reduction due to grouping occurs in end
bearing pile.
• For combined end bearing pile and friction pile
only the load carrying capacity of a group of
friction piles is reduced.

32. Group of Piles

33. Pile Cap
• When a column or pier is supported on one pile
only, the column should rest centrally on pile.
• However, when the column or any other load carrying
structural component is supported on more than one
pile, the piles should be connected through a rigid
pile cap, to distribute the load to the individual piles.

34. Pile Cap

35. Pile Cap
• The pile cap consists of a rigid, deep,
reinforced concrete slab which acts
monolithically with the group of piles.
• The piles should be arranged symmetrically
about the axis of the column so that the load
from column is distributed uniformly to all the
piles.

36. Pile Cap

37. Pile Cap
• The pile cap slab is provided of uniform thickness.
The pile cap should be extended beyond exterior piles
by 10 to 15 cm.
• The pile should be embedded by at least 15 cm in the
pile cap, and the reinforcement in the cap should be
placed at least 10 cm above the pile head.
• The pile cap provided over the entire of piles is
considered to be divided into a framework of
rectangular beams, along which main reinforcement
is provided. The arrangement of these beams depends
upon the number of piles and the width of beam is
taken equal to the width of the pile.

38. Pile Cap

39. Pile Shoe
• Where piles are driven wholly in soft soils
no shoe need be provided.
• The ends of the piles are usually cast in the
shape of a blunt point.
• A sharper point is preferred for driving into
hard clays or compact sands and gravels.

40. Pile Shoe
• The metal drive shoe commonly seen on concrete
piles whether driven in soft or hard conditions is
based on a design used to stop timber piles from
splitting or booming, and in soft conditions no metal
shoe of any kind is required.
• Where the piles are to be driven into soil containing
large cobbles or boulders, a shoe is needed to split the
boulders or to prevent breaking of the toe when the pile
pushes large cobbles or boulders to one side.
• The area of the top of the metal shoe in contact with
the concrete of the pile should be large enough to
ensure that the compressive stress on the concrete is
within the safe limits.

41. Pile Shoe

42. Pile Shoe
• Where piles are required to penetrate rock, to
obtain lateral resistance for example, a special rock
point is used.
• This design is particularly suited to driving on to a
sloping rock surface when, under careful blows of a
heavy hammer with a short drop, the sharp edge of
the hollow ground point will bite into the rock so
preventing the point from slipping down the rock
surface.
• The point is seated into rock with very light blows of
the hammer until it is evident that the point is
wholly within rock; the hammer drop can then be
increased to ensure a satisfactory penetration of the
point.

43. Pile Shoe

44. Load Tests on Piles
• Pile load test is a reliable method of
determining the carrying capacity of a pile.
• It can be performed either on a working pile
which forms the foundation of the structure or
on a test pile.

45. Load Tests on Piles

46. Load Tests on Piles
• The test load is applied with the help of
calibrated jack placed over a rigid circular
or square plate which in turn is placed on the
head of the pile projecting above ground level.
The reaction of the jack is borne by a truss
or platform which may have gravity loading
in the form of sand bag etc. or alternatively,
the truss can be anchored to the ground with
the help of anchor piles.

47. Load Tests on Piles

48. Load Tests on Piles
• The load is applied in equal increments of
about one-fifth of the estimated allowable load.
• The settlement are recorded with the help of
three dial gauges of sensitivity 0.02 mm,
symmetrical arranged over the test plate, and
fixed to an independent datum bar.
• A remote controlled pumping unit may be used
for hydraulic jack. Each load increment is kept
for sufficient time till the rate of settlement
becomes less than 0.02 mm per hour. The test
piles are loaded untill ultimate load is reached.

49. Load Tests on Piles

50. Load Tests on Piles
• The result are plotted in the form of load-settlement
curve approaching vertical.
• If the ultimate load cannot be obtained from the load
settlement curve, the allowable load is taken as;
• One-half to one-third the final load which causes
settlement equal to 10 % of the pile diameter.
• Two-third of the final load which causes a settlement
of 12 mm
• Two-third of final load which causes a net settlement
of 6 mm

51. Load Tests on Piles

52. Spacing of Piles
• The factors to be considered while deciding the pile
spacing are as follows:
• The nature of soil through which pile is driven.
• The obstruction during pile driving.
• The type of pile.
• The depth of penetration.
• The area of c/s of the pile.
• The center to center distance of piles in a group.
• The manner in which the pile supports the load.
• The material of pile.
• The damage to adjacent piles during pile driving operation.

53. Spacing of Piles

54. Pile Driving
• Piles are commonly driven by means of a
hammer supported by a crane or by a special
device known as a pile driver.
• The hammer is guided between two parallel
steel members known as leads.
• The leads are carried on a frame in such a way
that they can be supported in a vertical position
or an inclined position.
• Hammer are of the following types.

55. Pile Driving

56. Pile Driving
• Drop Hammer.
• If a hammer is raised by winch and allowed to fall
by gravity on the top of a pile, it is called a drop
hammer.
• Single Acting Hammer.
• If the hammer is raised by steam, compressed air
or internal combustion, but is allowed to fall by
gravity alone, it is called a single acting hammer.
The energy of such hammer is equal to the weight of
the ram times the height of fall.

57. Drop hammer

58. Single Acting Hammer

59. Pile Driving
• Double Acting Hammer: the double acting hammer
employs steam or air for lifting the ram and for
accelerating the downward stroke. It operates with
succession of rapid blows.
• Diesel hammer: The diesel hammer is a small,
light weight self-contained and self-acting type,
using gasoline for fuel. The total driving energy is
the sum of the impact of the ram plus the energy
delivered by explosion.

60. Double Acting Hammer

61. Diesel hammer

62. Pile Driving
• Vibratory hammer: The driving unit vibrates at high
frequency.
• During pile driving heads, helmets or caps are placed on the
top of the pile to receive the blows of the hammer of the
pile. A cushion, consisting of a pad of resilient materials,
hard wood or rope, is placed between the driving cap and
the top of pile to protect the pile head.
• Single acting hammer are advantageous when driving heavy
piles in compact or hard soil, while double acting hammers
are generally used to drive piles of light or moderate
weights in soils of average resistance against driving.
• Piles are ordinarily driven to a resistance measured by
the number of blows required for the last 1 cm of
penetration.

63. Vibratory Hammer

64. Load Carrying Capacity of Piles
• The ultimate load carrying capacity, or ultimate bearing capacity.
Or the ultimate bearing resistance Qf of a pile is defined as the
maximum load which can be carried by a pile, and at which the pile
continues to sink without further increase of load.
The allowable load Qa is the safe load which is the pile can carry safely and
is determined on the basis of
• (i) Ultimate bearing resistance divided by suitable factor of safety.
• (ii) The Permissible Settlement, and
• (iii) Overall stability of the pile-foundation.
• The load carrying stability of a pile can be determined by the following
method:
• 1. Dynamic Formulae
• 2. Static Formulae
• 3. Pile load tests
• 4. Penetration tests

65. Load Carrying Capacity of Piles
• (1) Engineering News formula: The engineering News formula was
proposed by A.M. Wellington (1818) in the following general form
• Qa = WH
F(S+C)
• Where Qa= allowable load
• W= Weight of hammer
• H= Height of fall
• F= Factor of safety=6
• S= final set per blow, usually taken as average penetration, cm per
blow for the last 5 blows of a drop hammer, or 20 blows of a stream
hammer.
• C= empirical constant

67. Load Carrying Capacity of Piles
Denoting weight W in kg, H in cm, S in cm,
And C= 0.25 cm for single and double acting
hammers, The above formulae reduces to the
following forms:
(i) Drop hammers:
Qa = WH
6(S+ 2.5)

68. Load Carrying Capacity of Piles
(ii) Single acting steam hammer:
Qa = WH
6(S + 0.25)
(iii) Double acting hammers:
Qa = (W + a p) H
6(S + 0.25)
Where,
a= effective area of piston (cm 2)
p= mean effecting steam pressure (kg/cm 2)

69. Load Carrying Capacity of Piles
• Hiley’s formula: Indian standard IS : 2911 (Part-I) 1964
gives the following formulae based of original expression of
Hiley:
Qf= Ƞh WH Ƞb
S + C/2
Where,
Qf= Ultimate load on pile
W= Weight of hammer, in kg
H= Height of drop of hammer, in cm
S= penetration or set, in cm per blow
C= total elastic compression = C1 + C2+ C 3

70. Load Carrying Capacity of Piles

71. Load Carrying Capacity of Piles
• C1 , C2, C 3 = temporary elastic compression of dolly
and packing pile and soil respectively.
• Ƞh= efficiency of hammer, variable from 65 % for
some double acting hammer to 100 % from drop
hammers released by trigger
• Ƞb= efficiency of hammer blow
Ƞb= W + e2 P
W + P

72. Load Carrying Capacity of Piles
Ƞb= W + e2 P W + e 2 P 2
W + P W + P
• P= Weight of pile, helmet, follower
• e= Coefficient of restitution
• For double acting hammers, the rated energy in
the same length as S and C is substituted for WH.
• The allowable load is obtained by using a factor
of safety of 2 to 2.5

73. Static Formulae
• The static formulae are based on assumption that the ultimate
bearing capacity Qf of a pile is the sum of the total ultimate skin
friction Rf and total ultimate point or end bearing resistance Rp:
• Q f = Rf + R p
• Qf= As.r f + Ap.r p
Where,
• A s = Surface area of pile upon which the skin friction acts
• A p = area of cross-section of pile on which bearing resistance acts.
For tapered piles, A may be taken as the cross-sectional area at the
lower one-third of the embedded length.
• r f = average skin friction
• R p = unit point or toe resistance
• A factor of safety of 3 may be adopted for finding the allowable
load.

74. Pulling of Piles
The various reasons of pulling out of piles from their
positions are as follows:
• The pile are removed or pulled out, which are
driven temporarily, as in case of a cofferdam.
• To replace the damaged piles during the driving
operations.
• To prepare the data of the strata through which
piles are to be driven by carrying out pulling tests.

75. Pulling of Piles

76. Pulling of Piles
• To reuse the existing piles, when the structure
above the pile is demolished or when the design of
arrangement of piles is changed.
• The method adopted for pulling of piles may
depend upon the equipment's available, type of
pile, etc.
• The concrete piles cannot be pulled successfully
without damage and they cannot be reused.
• The water jet or compressed air or a combination
of both may be adopted to reduce the skin friction
during pulling operation.

77. The methods adopted are as follows:
• Use of double-acting steam hammers.
• Use of vibrators
• Use of pile extractors
• Use of electricity
• Use of tongs

78. Causes of Failure of Piles
The most common cause of failure of piles are as
follows:
• The actual load coming on the pile may be more than
designed load.
• The bad workmanship in case of cast-in-situ cement
concrete piles.
• The attack by insects, etc. on wooden piles, causing the
decay of timber piles.
• The breakage due to overdriving especially in case of
timber piles.
• The damage due to abrasion resulting from the absence of
suitable protective covering.

79. Causes of Failure of Piles

80. Causes of Failure of Piles
• The buckling of piles due to removal of side support,
inadequate lateral support.
• The improper classification of soils.
• The improper choice of type of pile.
• The improper choice of the method of driving the
pile.
• The lateral forces not being taken into the design
of the pile.
• The wrongful use of pile formula for determining
its load bearing capacity.

81. Causes of Failure of Piles

82. References
• Failure Of Pile Foundation & Remedies
https://theconstructor.org/geotechnical/failure-of-pile-foundation-remedies/7377/
• Load Test on Piles
https://theconstructor.org/geotechnical/load-tests-on-piles/7430/
• Pile Foundations
http://www.understandconstruction.com/pile-foundations.html
• Types of Foundations
http://www.understandconstruction.com/types-of-foundations.html
• Types of Piles: Their Characteristics and General Use
onlinepubs.trb.org/Onlinepubs/hrr/1970/333/333-002.pdf
• What is a Pier Foundation?
https://civiltoday.com/geotechnical-engineering/foundation-engineering/deep-foundation/119-
what-is-a-pier-foundation-details-types-advantages-location

83. Thanks…